Interview with PE's Ukrainian colleague

[koraks]

dye couplers

But that's the thing - Kodachrome was not a dye coupler tech film, was it? As said above, the complete dyes were added to the film during processing. Chemically entirely dissimilar to the coupler technology used in all present color film and paper.

 

[LeoniD]

But that's the thing - Kodachrome was not a dye coupler tech film, was it? As said above, the complete dyes were added to the film during processing. Chemically entirely dissimilar to the coupler technology used in all present color film and paper.

No, it still uses the same general mechanism as the chromogenic monopacks we all know and love. The only difference is solubility of the couplers

 

[fert]

Why is it that most of Kodak's potions are developed with sodium salts, if they were developed with potassium salts they would be better concentrated.

 

[Sirius Glass]

Why is it that most of Kodak's potions are developed with sodium salts, if they were developed with potassium salts they would be better concentrated.

But would that work as well. Kodak used people taking snapshots to finance a large R&D budget to answer such questions. Is better concentration all that much more useful?

 

[Rudeofus]

One question, which obviously still burns under everyone's nails - after Ron left it unanswered: is there a measurable effect from using a Citric Acid based stop bath on color film? Ron claimed one should never use Citric Acid, but couldn't remember the exact reason for this.

One more question if I may:

There are articles and patents, which claim, that a slight addition of a phenidone type product increases speed of color developers, both in film speed and in speed of development. At the same time I never ran across a product from Fuji or Kodak, where this effect has been used. I have seen this effect in my own experiments, and no, it's not that mythical "half stop speed boost", but it's detectable and one should have reasons to forego it.

Has this ever been tried in his research lab? Could he elaborate on that?

 

[koraks]

is there a measurable effect from using a Citric Acid based stop bath on color film? Ron claimed one should never use Citric Acid, but couldn't remember the exact reason for this.

Hehe, yeah, see #4 - that was literally the first one I thought of, too!

Is better concentration all that much more useful?

Yes, it is, in terms of logistics, convenience etc. It makes quite a difference if you can offer e.g. a paper developer that the user can use at 1+10 or vs one that can't be diluted further down than 1+2. Plenty of formulas (esp. developers) exploit the better solubility of potassium salts compared to their sodium counterparts.

 

[mshchem]

Since modern color negative film has about 6 stops of latitude, why worry about a half stop of speed boost?

 

[Sirius Glass]

Since modern color negative film has about 6 stops of latitude, why worry about a half stop of speed boost?

I strongly agree.

 

[Rudeofus]

Since modern color negative film has about 6 stops of latitude, why worry about a half stop of speed boost?

Because these 6 stops of latitude exist upwards (i.e. towards stronger exposures), while a speed boost increases capabilities downwards, i.e. towards weaker exposures. I still struggle with the fact, that a child's birthday event needs EI at or beyond 3200 to become tenable with ambient light only. And yes, I do realize, that +1/4 stop of speed will not improve my situation here.

 

[mshchem]

Because these 6 stops of latitude exist upwards (i.e. towards stronger exposures), while a speed boost increases capabilities downwards, i.e. towards weaker exposures. I still struggle with the fact, that a child's birthday event needs EI at or beyond 3200 to become tenable with ambient light only. And yes, I do realize, that +1/4 stop of speed will not improve my situation here.

My Dad recorded our family using an Argus C3, (pretty nice camera) and Kodachrome ASA 10. Made great pictures with 25B press flash bulbs. When I shoot reversal film I usually bracket by 1/3 or 1/2 stop. Not much room for me messing up with slide film.

 

[MattKing]

Made great pictures with 25B press flash bulbs.

Of course, his kids still have bright flash related images burned into their retinas
My similar memories involved Photofloods and Kodachrome in Double 8.

 

[mshchem]

Of course, his kids still have bright flash related images burned into their retinas
My similar memories involved Photofloods and Kodachrome in Double 8.

Double 8, far superior to Super 8. I used one of these to make a film in 10th grade. Had to be able to superimpose titles!

Yep today's kids don't have the joy of listening to the bulb crackle after detonation, I remember the smell and the sound, since I was blind for 2 minutes afterwards. After I regained my sight I could see that the Bluedot had turned black